Spectrophotometer color measurement with a target illumination system and
a reflected illumination sensing system where the target surface is
variably spaced from said spectrophotometer. Color correction calibration
information corresponding to color measurements for known different
spacings of a test target surface from the spectrophotometer are obtained
and stored. In use, the spacing of the actual target surface from the
spectrophotometer is measured to provide a target spacing information
signal. That signal is automatically combined with the stored color
correction calibration information for the corresponding distances to
provide at least partial correction of color measurement errors of the
spectrophotometer for variable spacing of the target surface relative to
the spectrophotometer even with low cost fixed focus optics. The
spectrophotometer output can be so corrected by changing the target
illumination, such as by LED pulse width changes, and/or by corrective
adjustment of the measured reflectances.